Peter Alfred Ziegler (November 2, 1928 – July 19, 2013) was a Swiss geologist, who made contributions to the understanding of the geological evolution of Europe and the North Atlantic borderlands, of intraplate tectonics and of plate tectonic controls on the evolution and hydrocarbon potential of sedimentary basins. Ziegler’s career consists of 33 years as exploration geologist with the petroleum industry, 30 of which with Shell, and 20 years of university teaching and research.